Answer: Salmonellosis is a disease caused by bacteria of the genus Salmonella. These organisms are common in animals and people.

They are named for Daniel Salmon, a veterinarian, who studied them. There are more than 2,000 Salmonella types worldwide. Many have fancy names and sometimes produce disease. Eggs can be infected if hens are Salmonella carriers, but they are only one source of Salmonella infections.

Salmonella dwell harmoniously in the gut of many animals and people. They are excreted in the feces. They survive and multiply wherever fecal contamination exists. They are present in barnyards; chicken pens; litter boxes; manure piles; bird, turtle, and snake cages; human waste water; and in bathrooms where toilet handles, water faucets, and doorknobs can be contaminated.

Human infections can be reduced by scrubbing hands after exposure to these risks and keeping fingers out of your mouth.

After washing hands, door handles should be grasped with dry paper towels. Hand sanitizers should be applied after leaving restrooms and before handling food or eating.

Foods can be infected by soiled hands, utensils or counters where raw chicken or meat is cut. Salmonella outbreaks occur when exposed salads sit unrefrigerated for hours and the organisms multiply rapidly.

Salmonella are major causes of human bacterial food poisoning. The danger can be reduced by pasteurizing or cooking eggs and foods of animal origin and by washing raw fruits and vegetables.

Human symptoms vary from unnoticed infections to diarrhea, stomach cramps, fever, vomiting or dehydration. This occurs most often when Salmonella are acquired in massive doses by people with little previous exposure, who have no immunity to the infecting type. They produce serious illness in infants, senior citizens and those with immunological disorders.

Most animals are susceptible to multiple Salmonella types. Young animals are most likely to suffer severe disease. Signs in animals vary but can include fever, diarrhea, dehydration, depression, and weight loss.

Sanitation and avoidance of crowding are the recommended preventive strategies. This is difficult where intensive management and close-confinement of animals is practiced. Some Salmonella types infect a single animal species and others infect many species.

Salmonella infections in adult animals are usually mild. However, when the infecting dose is large the infecting Salmonella are highly pathogenic, or the environmental stress is excessive, disease can result.

Salmonella vaccines are used with mixed success because the multiplicity of Salmonella types makes matching vaccines with local organisms difficult.

Research and experience has provided progress in understanding Salmonella. However, they have an amazing capacity to survive and resurface from time to time.